Systems and methods for immobilization with repetition rate control

Abstract

An apparatus impedes locomotion by a human or animal target by conducting a current through the target. The apparatus includes a battery, a circuit, and a processor. The circuit charges a capacitance to a predetermined voltage and discharges the capacitance to provide a pulse of the current. Charging occupies a first interval having a duration, the duration affected by an operating condition of the battery. The processor controls the circuit to provide a first series of pulses of the current, the first series having a first pulse repetition rate, the first pulse repetition rate being compensated by the processor for variations in the duration of the first interval.

1. An apparatus for impeding locomotion by a human or animal target by conducting a current through the target, the apparatus comprising:
 a battery; 
 a circuit that charges a capacitance to a predetermined voltage, and that discharges the capacitance to provide a pulse of the current, wherein charging occupies a first interval having a duration, the duration affected by an operating condition of the battery; 
 a processor that controls the circuit to provide a first series of pulses of the current, the first series having a first pulse repetition rate, the first pulse repetition rate being compensated by the processor for variations in the duration of the first interval. 
 
   
   
     2. The apparatus of  claim 1  wherein the operating condition of the battery comprises a temperature of the battery. 
   
   
     3. The apparatus of  claim 1  wherein:
 the circuit charges the capacitance in response to a signal; and 
 the processor provides the signal to control the circuit. 
 
   
   
     4. The apparatus of  claim 3  wherein the circuit is responsive to an oscillation frequency of the signal. 
   
   
     5. The apparatus of  claim 3  wherein the circuit is responsive to an oscillation frequency of the signal of about 500 Hz. 
   
   
     6. The apparatus of  claim 5  wherein the processor compensates by delaying provision of the oscillation of the signal. 
   
   
     7. The apparatus of  claim 1  wherein, after providing the first series of pulses, the processor further controls the circuit to provide a second series of pulses having a second pulse repetition rate, the second pulse repetition rate being compensated by the processor for variation due to the operating condition of the battery. 
   
   
     8. The apparatus of  claim 1  wherein:
 the circuit further comprises a spark gap having a breakdown voltage; and 
 the predetermined voltage is substantially the same in magnitude as the breakdown voltage. 
 
   
   
     9. The apparatus of  claim 8  wherein:
 the capacitance further comprises a first capacitor and a second capacitor; 
 the circuit charges the first capacitor sufficient to cause the gap to conduct; and 
 the circuit charges the second capacitor to a voltage sufficient for impeding locomotion by the target. 
 
   
   
     10. A method, performed by an apparatus, the apparatus for impeding locomotion by a human or animal target by conducting a current through the target, the method comprising:
 charging a capacitance of the apparatus with energy from a battery of the apparatus to a predetermined voltage, charging occupying a first interval having a duration, the duration in accordance with an operating condition of the battery; 
 discharging the capacitance to provide the current; 
 repeating charging and discharging to provide the current at a repetition rate having a period; and 
 delaying, before repeating, to provide the period compensated for variations in the duration of the first interval. 
 
   
   
     11. The method of  claim 10  wherein charging further comprises providing a signal to a circuit of the apparatus that charges the capacitance. 
   
   
     12. The method of  claim 11  delaying comprises providing the signal to the circuit after a delay. 
   
   
     13. The method of  claim 10  wherein a delay of delaying consists essentially of the period minus the duration of the first interval. 
   
   
     14. The method of  claim 10  wherein charging further comprises:
 charging a first capacitor of the capacitance to a voltage sufficient to cause a spark gap of the apparatus to conduct; and 
 charging a second capacitor of the capacitance to a voltage sufficient for impeding locomotion by the target. 
 
   
   
     15. The method of  claim 10  wherein discharging further comprises causing a spark gap of the apparatus to conduct. 
   
   
     16. The method of  claim 10  wherein discharging further comprises:
 coupling a first capacitor of the capacitance to a voltage multiplier of the apparatus, wherein the voltage multiplier is coupled to an electrode of the apparatus that conducts the current; 
 discharging the first capacitor; 
 coupling a second capacitor of the capacitance to the electrode; and 
 discharging the second capacitor.